Use of LabVIEW as Local Supervision for the
LEP Cooling and Ventilation Control System

Marc Vadon, CERN

The LEP cooling, ventilation, and fire security systems were designed and built in the 80's using turnkey equipment controlled by PLCs. Their integration in the LEP service network was performed at CERN, but for budgetary reasons, most of the local supervision consoles were not installed. The need for such an equipment became crucial since the performance of LEP was increasing rapidly, requiring better control of the environmental parameters of the machine. In 1994, a local supervision system was developed in close collaboration with the operation and maintenance team, using an industrial software package: LabVIEW. The use of graphical programming allowed the person responsible for each process to take care of the bulk of the development. The project was completed in about a year and fits closely to our needs that are distinct from those of a central control room: trend and failure analysis, historical behaviour and process optimisation. We eventually integrated all 15 processes on the 8 points of LEP which adds up to 30,000 points of measurement. Data are stored at one minute interval for later use. By the means of a video cassette recorder-like MMI the operator can navigate in time synchronously on any of the synoptics. Long term archiving with automatic data compression is also implemented. The project is now complete and has reached the primary goal of improving the operating efficiency of the HVAC systems serving the accelerator. These points, their associated resources and costs will be developed in the presentation.